SUMMARYAn ascomycete collected frequently from wood submerged in the estuarine portion of the Patuxent River, Maryland, is described as a new genus in the family Halosphaeriaceae. It is most closely related to two monotypic genera in this family,Nais inornataandLignincola laevis; however, it differs from both of them in color and morphology of the perithecium and in ascus and ascospore structure.